Mary’s comment about the teachers only wanting to look at the girl’s knickers suggests the possibility of male teachers raising girls’ skirts to cane or slipper them. A quite fascinating prospect, crying out for further investigation.
There is another possibility here, and this is why it struck a chord with me. I taught at a mixed secondary modern school (which later converted to a comprehensive) between the late sixties and late seventies. The corporal punishment rule was that boys could be caned on either bottom or hand, but girls could only be caned on their hands. However, we were allowed to slipper girls on their bottoms (a rule which made those years the most enjoyable of my life – but enough said about that for now).
We were not allowed to remove or adjust any clothing – on boys or girls – but there were occasions when this rule, or at least its intended purpose, was able to be circumvented.